Car coupler



Aug. 9, 1960 w. J. METZGER' CAR COUPLER Filed Feb. 28, 1957 INVENTOR.

WILLIAM J METZ'GEE BY $17 .ATTURNE Y CAR COUPLER William J. Metzger, East Cleveland, Ohio, assignor to National Malleable and Steel Castings Company, Cleveland, Ohio, a corporation of Ohio Filed Feb. 28, 1957, Ser. No. 643,101

3 Claims. (:Cl. 213-151) This invention relates to draw bars, or car couplers,

as they are more commonly known in the art, and more particularly to car couplers of the knuckle type.

It has been found that in knuckle type couplers, there sometimes occurs, in service, structural failure of the coupler in the vicinity of the juncture of the coupler head and the coupler shank, the latter mentioned location being a critical area of stress concentration in the coupler.

The present invention provides a novel construction of car coupler which substantially strengthens the latter in the above referred to critical location and thus prevents structural failure of the coupler.

Accordingly, the primary object of the invention is to provide a knuckle type car coupler construction that prevents structural failure of the coupler in the vicinity of the juncture of the coupler head and coupler shank.

Another object of the invention is to provide a car coupler shank for a knuckle type car coupler comprising walls having a novel configuration wherein'the strength of the coupler in the vicinity of the juncture of the shank and the coupler head is materially increased over that of prior art constructions of coupler shanks.

A more specific object of the invention is to provide a car coupler of the knuckle type comprising a hollow shank of polygonal configuration in vertical cross-section, wherein the walls of the shank, in the vicinity of the'juncture of the coupler head and the shank, are so contoured as to-compensate for the off-center pulling forces and resultanteccentric stresses applied to the coupler during operation of the latter in service. r r

Other features and advantages of the invention will be apparent from thefol'lowing description; taken in conjunction with the drawings, wherein: a p

a Fig. lis a fragmentary sectional plan view of a knuckle type car coupler embodying the invention. I

Fig. 2 is a vertical sectional view taken along line 2-2 of Fig. 1 and represents the general location of the juncture of the coupler head and shank.

Fig. 3 is a vertical sectional 'view taken along line 3-3 ofFig.2." i

Referring to the drawings, there is shown an Engine Type A.A.R. Standard E coupler comprising a head 10 and a hollow-shank lzrigidly joined-with the head and extending rearwardly therefrom. Head 10 comprises side walls 14 and 16- partially defining a chaniber ll lifor-ireceivingthe knuckle of the coupler. Wall idmerges with slotted outer wall 117 to form a'guard arm 19 on one side of the coupler'head Knuckle 20 is pivotally mounted on... the coupler'head'iruthe usual manner by meanslof vertical pin 2.2 p v,

. The knuckle'coinprises a nose portion 24Jwhich' is adapted to interlock inn swan inanner with the nose portion of a mated coupler, and a'tail portion 26 which is received in the aforementioned coupler head chamber 18. Knuckle 20 is adapted to be locked by a vertically movable lock (not shown) and to be thrown to open position by a horizontally movable knuckle thrower (not ICE 2 shown), all of which parts and operation thereof are 'well known to those skilled the art.

The knuckle 20 seats onlower car 28 disposed on one side of the coupler head and comprises top and bottom pulling lugs 30 on the tail portion 26 thereof (the bottom lug not being shown but being similar to the top lug). Lugs 30 are adapted to engage corresponding top and bottom lugs 32 and 34 on the top and bottom walls of the coupler head in a manner well known to those skilled in the art. It will be seen that the pulling lugs are elfset to one side of the longitudinal center line XX of the coupler. Consequently, the pulling forces applied to the coupler in service will also be located to one side of the center line XX, thus causing the stresses which result during pulling operations to be eccentrically applied to the coupler. It will be apparent, therefore, that in existing knuckle couplers, a greater portion of the pulling stress is applied to the knuckle mounting side of the coupler, which is conducive to the aforementioned structural failure of the coupler in the vicinity of the head and shank juncture.

Shank 12. which in the embodiment shown has an outer surface contour in vertical cross-section. of generally retilinear configuration, comprises top and bottom walls 36 and 38 and side walls 44 and 42. As shown, the outer periphery of any crosssection of the portion of the shank immediately rearward of the head is rectangular and substantially dimensionally uniform. Walls 36, 38, 40 and 42 of the shank merge with the rearward portions of corresponding walls of the coupler head in the general vicinity designated by the letter A to form the integrally composed car coupler shank and head.

In accordance with the invention, the inner vertical side surface 42a of side wall 42 of the shank is sloped inwardly in'a forward direction (Fig. 1) so as to converge toward'longitudinal center line XX of the coupler, until the general area A of the juncture between coupler head 10 and coupler shank 12 is reached, after which side wall 4-2 curves outwardly as at 4'5 and merges with side wall 14' of the coupler head. I

The contour P of the inner surfaces of prior art construction of the A.A.R. Standard E Engine coupler shank is'shown in dotadash lines, and it will be seen that in the prior construction, the inner-side surface of wall 42 is disposed in a longitudinally extending vertical plane that runs generally parallel to the center line X--X of the coupler. Figs. 1 and 3 illustrate that the center line X -X is disposed generally midway between one pair of opposite outer surfaces. of the side walls 40 and 42.. The center line is also midway between another pair of opposite outer surfaces, i.e., the outer surfaces of the top and bottom walls 36 and 38. The surfaces of either pair are, as shown, straight in the lengthwise direction of the coupler, and approximately parallel to each other and to the center line The side surface 42a of the present arrangement is disposed in a generally diagonally extending vertical plane that is not disposed parallel with the center line XX- of the coupler but converges in a forward direction toward center line XX. In the embodiment shown, surface 42a is sloped inwardly at an angle of approximately 2 with respect to the corresponding side surface of the prior art construction P.

It will be seen that surface 42a of the present arrangement commences to'slopeinwardly in a forward direction at-a substantial distance rearwardly of the juncture 6f shank 12 and coupler head 10 and continues to diverge inwardly with respect to outer side surface 42b of side wall '42 until the general area A of the coupler head and shank juncture is reached, after which it curves outwardly as aforesaid and merges with the side Wall 14 of the coupler head. It will be understood that this slope of surface 42a substantially thickens wall 42 over that which exists in prior art constructions and thus strengthens the wall against the off-center pulling forces applied to the coupler in service. It will be noted that the maximum thickness or cross-sectional area of wall 42 exists in the general location A of the juncture of the coupler head and shank on the side of the coupler to which is appplied the greater portion of the pulling stresses. In both forward and rearward directions from such juncture, the thickness of the wall 42 decreases. As the drawing further indicates, the wall 42 is substantially thicker at area A than the wall 40 and portions of the walls 36 and 38 on the side of the vertical plane of the center line X- X toward the wall 40.

The upper and lower ends of the inner side surface 42a curve inwardly and merge with top and bottom sloping portions 36a and 38a of top and bottom walls 36 and 38 of the shank. In vertical cross-section (Fig. 2), portion 36a slopes inwardly and upwardly and portion 38a slopes inwardly and downwardly to merge with the adjacent horizontal portions 36b and 38b of top and bottom walls 36 and 38 respectively. It will be seen that in the embodiment shown, portions 36a and 38a merge with portions 36b and 38b at approximately the intersection of the coupler shank and an imaginary vertical plane containing the center line XX of the coupler. In the embodiment shown, portions 36a and 38a are sloped at approximately 7 degrees to the horizontal. Portions 36a and 38a of top and bottom walls 36 and 38 also slope inwardly in a forward direction (Fig. 3) to converge toward an imaginary horizontal plane containing center line X-X of the coupler. Thus portions 36a and 38a, in a direction transversely of the shank, converge inwardly relative to outer top surface 36c of top wall 36 and outer bottom surface 38c of bottom wall 38, respectively. It will be seen from Fig. 3 that, in a direction longitudinally of the shank, portions 366: and 38a slope inwardly, commencing at a substantial distance rearwardly of the juncture of shank 12 and coupler head 10, until the general area A of the head and shank juncture is reached, after which portions 36a and 38a curve outwardly and merge with top and bottom walls of the coupler head. It will be understood, therefore, that top and bottom walls 36 and 38 are progressively thickened in a transverse direction, commencing at the imaginary longitudinal vertical center plane of the coupler and extending to the juncture of walls 36 and 38 with side wall 42 of the shank. Walls 36 and 38 also are progressively thickened in a longitudinal direction, commencing at a point rearwardly of the coupler head and shank juncture and extending forwardly to the latter. Thus, the maximum thickness or cross-sectional area of walls 36 and 38 exists in the general location A of the coupler head and shank juncture on the knuckle side of the coupler, which is the side subjected to the greater portion of the pulling stresses.

It will be seen that in vertical cross-section (Fig. 2), the inner surfaces of the juncture of the coupler shank and the head in the prior art construction comprise a generally rectangular configuration while the novel contour of the inner surfaces of the herein disclosed arrangement comprises a generally hexagonal configuration. This generally hexagonal configuration in vertical cross-section provides a much stronger coupler for absorbing pulling stresses, and one which will not fail structurally in service.

The present novel contour of the inner surfaces of the coupler shank compensates for the aforedescribed eccentric stress condition in the coupler without any substantial increase in coupler weight. This is an important advantage, since any substantial increase in weight of a car coupler obviously presents additional shipping, handling and maintenance problems, as well as making the coupler less desirable from an economic standpoint.

While the invention has been shown embodied in the Engine Type A.A.R. Standard E coupler, it will be understood that it can be advantageously applied to any knuckle type coupler in which, in service, the pulling forces are applied eccentrically to the coupler.

From the foregoing description and accompanying drawings it will be readily understood that the invention provides a novel contour for the inner surfaces of the hollow coupler shank of a knuckle type coupler which compensates for the eccentric or off-center pulling stresses applied to the coupler in service and thus prevents structural failure of the coupler in the critical area of the juncture of the coupler head and shank.

The terms and expressions which have been employed are used as terms of description and not of limitation and there is no intention of excluding such equivalents of the invention described or of the portions thereof as fall within the purview of the claims.

What is claimed is:

1. In a car coupler comprising a head; a hollow shank extending rearwardly lengthwise of a longitudinal center line of the coupler from a rigid juncture with the head; the shank having bottom and top walls and opposite side walls of which the outer surfaces are arranged in two opposite facing pairs with respect to which said center line is centered between the surfaces of each pair; each of said surfaces being straight in a lengthwise direction of the coupler; a knuckle supported by said head along an axis in laterally spaced relation with a normally vertical center plane containing said center line; said side walls being generally uniform in thickness except for a thickened forward portion of the side wall on the same side of said center plane as said knuckle axis; the thickness of said thickened side wall portion being a maximum at said juncture and decreasing rearwardly from the juncture to said uniform thickness.

2. The car coupler of claim 1 wherein: the top and bottom wall portions have a substantially uniform thickness except for a thickened portion of each disposed between said center plane and said thickened side wall portion; said thickened top and bottom wall portions increasing in thickness in a transverse direction from the center plane to the thickened side wall portion and being of maximum thickness adjacent said juncture and said side wall portion, and decreasing rearwardly from the juncture in thickness to said uniform thickness of the top and bottom walls.

3. The car coupler of claim 2 wherein: at said juncture said thickened top and bottom wall portions are inclined, starting at said vertical center plane, an angle of 7 degrees with respect to a normally horizontal center plane perpendicular to said normally vertical center plane and containing said center line; and said thickened portions of the top wall, bottom wall, and side wall have approximately equal maximum thicknesses at said juncture and are of equal length rearwardly from the juncture.

References Cited in the file of this patent UNITED STATES PATENTS 271,216 'Burkhardt Jan. 30, 1883 353,320 Lorraine Nov. 30, 1886 416,187 Smillie Dec. 3, 1889 448,406 Bissell Mar. 17, 1891 471,881 McConway Mar. 29, 1892 476,450 Donahue June 7, 1892 547,495 Moonmaw Oct. 8, 1895 2,007,451 Kinne July 9, 1935 tunnel in. 

